Psila merdaria / fimetaria

Hi,

Think I'm happy with this as Psila merdaria but would be grateful of confirmation as I've never seen fimetaria and the pilosity on the arista looks quite long. Only very slight darkening at the base though.

Re: Psila merdaria / fimetaria

I'm bound to confess that I've never been happy with the couplet that differentiates between these two species.Particularly hard in photographs where shadows may be mistaken for darkening.Someone with a good series of specimens may be able to come up with a better diagnostic feature (especially from ordinary photographs).Until then, treat the Atlas records as "Psila spp." to be on the safe side. There's no clear biogeographic (or phenologic) pattern which separates them either.

Re: Psila merdaria / fimetaria

I agree with Darwyn that separating these species is not always straightforward. While short aristal hairs probably indicate merdaria, I have seen long aristal hairs in both species. I often end up dissecting them to confirm identity, especially as I seem to find specimens with no antennae very regularly!